Environmental Assessment for Water Quality of the White Nile River in Khartoum State

Abstract

The aim of this study was to assess the environmental quality of the White Nile water and identify pollution sources in Khartoum state (Aldabasin area was taken as a case study) because the area is located by many factories, sewage treatment plants and service institutions, after investigation and follow-up to find out the sources of pollution of the Nile in this area, it was found that there is drain system in this area directly drain into the Nile. The drain system consists of the joining of two drains sources: Soba Sewage Treatment Plant then the treated waste water of soba passing Elyarmouk military complex and the other drain is Rainwater in this area , Although it was noted that some physical characteristics such as the color and smell of this water showed that it is undoubtedly the drain system is the main cause of the pollution . but to achieve this goal and make sure ,water samples were taken from different points, the first water sample was taken before the treatment in Soba sewage treatment plant and the second sample after the treatment, the third sample was taken from the drain system immediately after water treated in Soba treatment plant and then passed Elyarmouk military complex. While the fourth sample was taken from the White Nile at the distance 13 meters after the waste water entering to the river. The physical characteristics (temperature, hydrogen number and connectivity) were measured and analyzed for all these points , the result showed that all these physical characteristics are within the acceptable and permitted limit as defined by the Sudanese Authority for Specifications and Standards for Liquid waste after treatment as well as specifications specified by the World Health Organization , Chemical tests were also conducted for the same samples, (Total suspended solids, Total dissolved solids salts, biological oxygen demand, chemical oxygen demand and heavy metals) and the results showed that all samples exceeded the ratios set by the Sudanese Authority for Specifications and Standards for Liquid waste after treatment as well as specifications specified by the World Health Organization, that means : - Contamination of the White Nile water with sewage water, which was clearly reflected in the results of the biological oxygen demand and chemical oxygen demand by the analysis of the sample taken from the Nile, the results were (315- 512 mg/l) respectively, while the allowable limit was (15-75 mg/l) respectively. V - Contamination of white Nile water with industrial wastewater, which is explained by the increasing of lead and cadmium metal in the Nile water where it was found for the same sample (0.21-0.0025 mg/l )respectively while the allowable limit (0.1-0.003mg/l) respectively. So the main sources of Nile water pollution are: - Soba sewage plant, which explained by the results of the analysis of samples before and after treatment, where it was noted that the biological oxygen demand was (290-270 mg/l) for samples before and after treatment respectively and chemical oxygen demand was (560-554 mg/l) respectively. -Elyarmouk military complex, which is explained by the increasing of heavy metals in the drain system after the water treated in soba and passing Elyarmouk military complex where the result of lead and cadmium for the samples was (0.16-0.007mg/l) respectively and for samples after treatment at Soba station (0.004-0.02mg/l) respectively.